{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 6:Electrical Conducting and Insulating Materials" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 6.1,Page No:6.8" ] }, { "cell_type": "code", "execution_count": 1, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "temperature coefficient =0.00082 K**-1\n" ] } ], "source": [ "import math\n", "\n", "#variable declaration\n", "R75 = 57.2; #resistance at 75 C in Ω\n", "R25 = 55; #resistance at 25 C in Ω\n", "t1 = 25; #temperature in C\n", "t2 = 75 # temperature in C\n", "\n", "#formula\n", "#Rt = R0*(1+(alpha*t))\n", "#calculation\n", "alpha = (R25-R75)/float((25*R75)-(75*R25)); #temperature cofficient\n", "\n", "\n", "#result\n", "print'temperature coefficient =%3.5f'%alpha,'K**-1';\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 6.2,Page No:6.9" ] }, { "cell_type": "code", "execution_count": 2, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "temperature coefficient of resistance =65.06 °C\n" ] } ], "source": [ "import math\n", "\n", "#variable declaration\n", "R1 = 50; #resistance in ohm at temperature 15°C\n", "R2 = 60; # resistance in ohm temperature 15°C\n", "t1 = 15; #temperature in °C\n", "alpha = 0.00425; #temperature coefficient of resistance\n", "\n", "\n", "#formula\n", "#Rt = R0*(1+(alpha*t))\n", "#Rt1/Rt2 = R0*(1+(alpha*t1))/R0*(1+(alpha*t2))\n", "#calculation\n", "R = R2/float(R1); #resistance in Ω\n", "X = 1+(alpha*t1);\n", "t2 = ((R*X)-1)/float(alpha); #temperature coefficient of resistance in °C\n", " \n", " \n", "\n", "#result\n", "print'temperature coefficient of resistance =%3.2f'%t2,'°C';" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 6.3,Page No:6.9" ] }, { "cell_type": "code", "execution_count": 3, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Hence temperature under normal condition is 3320.00 °C\n" ] } ], "source": [ "import math\n", "\n", "#variable declaration\n", "t1 = 20; #temperature in °C\n", "alpha = 5*10**-3; #average temperature coefficient at 20°C \n", "R1 = 8; #resistance in Ω\n", "R2 = 140; #resistaance in Ω\n", " \n", " \n", "#calculation\n", "t2 = t1+((R2-R1)/float(R1*alpha)); #temperature in °C\n", " \n", "#result\n", "print'Hence temperature under normal condition is %3.2f'%t2,'°C';\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 6.4,Page No:6.10" ] }, { "cell_type": "code", "execution_count": 4, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "resistivity=4.80e-05 Ω-m\n" ] } ], "source": [ "import math\n", "\n", "#variable declaration\n", "l = 100; #length in cm\n", "d = 0.008; #diameter of wire in cm\n", "R = 95.5; #resistance in Ω\n", "d = 0.008; #diameter in cm\n", "\n", "\n", "#formula\n", "#R=p*l/A\n", "#calculation\n", "A = (math.pi*d*d)/float(4); #cross-sectional area\n", "p = (R*A)/float(l); #resistivity of wire in Ω-cm\n", "\n", "\n", "#result\n", "print'resistivity=%3.2e'%p,'Ω-m';" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 6.5,Page No:6.10" ] }, { "cell_type": "code", "execution_count": 5, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "percentage conductivity=93.59 %\n" ] } ], "source": [ "import math\n", "\n", "#variable declaration\n", "R0 =17.5; #resistance at 0 degree c in Ω\n", "alpha =0.00428; #temperature coefficient of copper in per °C\n", "t =16; #temperature in °C\n", "\n", "\n", "#calculations\n", "Rt = R0*(1+(alpha*t)); #resistance at 16 °C\n", "P = (R0/float(Rt))*100; #percentage conductivity at 16 °C\n", "\n", "\n", "#result\n", "print'percentage conductivity=%3.2f'%P,'%';" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 6.10,Page No:6.30" ] }, { "cell_type": "code", "execution_count": 6, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "insulation resistance= 16 Ω\n" ] } ], "source": [ "import math\n", "\n", "#variable declaration\n", "l = 60; #length in m\n", "r2 = 38/float(2); #radius of outer cylinder in m\n", "r1 = 18/float(2); #radius of inner cylinder in m\n", "p = 8000; #specific resistance in Ω-m\n", "\n", "#calculation\n", "R = (p/float(2*math.pi*l))*math.log(r2/float(r1)); #insulation resistance of liquid resistor in Ω\n", "\n", "#result\n", "print'insulation resistance=%3.0f '%R,'Ω';" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 6.11,Page No:6.30" ] }, { "cell_type": "code", "execution_count": 7, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "resistivity=3.358e+13 Ω-m\n" ] } ], "source": [ "import math\n", "\n", "#variable declaration\n", "d1 = 0.0018; #inner diameter in m\n", "d2 = 0.005; # outer diameter in m\n", "R = 1820*10**6; #insulation resistance in Ω\n", "l = 3000; #length in m\n", "\n", "#calculations\n", "r1 = d1/float(2); #inner radius in m\n", "r2 = d2/float(2); #outer radius in m\n", "p = (2*math.pi*l*R)/float(math.log(r2/float(r1))); #resistivity of dielectric in Ω-m\n", " \n", "#result\n", "print'resistivity=%3.3e'%p,'Ω-m';" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 6.12,Page No:6.31" ] }, { "cell_type": "code", "execution_count": 8, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "insulation resistance =1.606537e+08 Ω\n", " Note: calculation mistake in textbook in calculating insulating resistance\n" ] } ], "source": [ "import math\n", "\n", "#variable declaration\n", "d1 = 0.05; #inner diametr in m\n", "d2 = 0.07; #outer diameter in m \n", "l = 2000; #length in m\n", "p = 6*10**12; #specific resistance in Ω-m\n", " \n", "#calculations\n", "r1 = d1/float(2); #inner radius in m\n", "r2 = d2/float(2); #outer radius in m\n", "R = (p/float(2*math.pi*l))*(math.log(r2/float(r1))); #insulation resistance\n", " \n", " \n", "\n", "\n", "#result\n", "print'insulation resistance =%1e'%R,'Ω';\n", "print' Note: calculation mistake in textbook in calculating insulating resistance';" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 6.13,Page No:6.31" ] }, { "cell_type": "code", "execution_count": 9, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "capacitance =2.68e-10 F\n", " charge=6.696e-06 C\n" ] } ], "source": [ "import math\n", "\n", "#variable declaration\n", "a = 110*10**-3; #area in m**2\n", "d = 2; #thickness in mm\n", "er = 5; #relative permitivity\n", "E = 12.5*10**3; #electric field strength in V/mm\n", "e0 = 8.854*10**-12; #charge of electron in coulombs\n", " \n", " \n", "#calculations\n", "A = a*a; #area in m**2\n", "C = e0*((er*A)/float(d*10**-3)) #capacitance in F\n", "V = E*(d);\n", "Q = (C)*(V) #charge on capacitor in C\n", " \n", "#result\n", "print'capacitance =%3.2e'%C,'F';\n", "print' charge=%3.3e'%Q,'C';" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 6.14,Page No:6.31" ] }, { "cell_type": "code", "execution_count": 10, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "charge=7.50e-02 C\n", " electric flux=75.000 mc\n", " electric flux density=5.21 c/m**2\n", " electric field strength=1.000e+06 V/m\n" ] } ], "source": [ "import math\n", "\n", "#variable declaration\n", "I = 15*10**-3; #current in A\n", "t = 5; #time in s\n", "V = 1000; #voltage in volts\n", "d = 10**-3; #thickness in m\n", "a = 120*10**-3;\n", "\n", "#calculation\n", "A = a**2 #area in m**2\n", "Q = I*t; #charge on capacitor in C\n", "#since charge and electric field are equal\n", "phi = Q; #electric flux in mc\n", "D = Q/float(A); #electric flux density in c/m**2\n", "E = V/float(d); #electric field strength in dielectric\n", "\n", "#result\n", "print'charge=%3.2e'%Q,'C';\n", "print' electric flux=%4.3f'%(phi*10**3),'mc';\n", "print' electric flux density=%3.2f'%D,'c/m**2';\n", "print' electric field strength=%2.3e'%E,'V/m';\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 6.15,Page No:6.32" ] }, { "cell_type": "code", "execution_count": 11, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "capacitance=7.0124e-09 F\n" ] } ], "source": [ "import math\n", "\n", "#variable declaration\n", "n = 12; #number of plates\n", "er = 4; #relative permitivty \n", "d = 1.0*10**-3; #distance between plates in m\n", "A = 120*150*10**-6; #area in m**2\n", "e0 = 8.854*10**-12; # in F/m\n", "\n", "#calculation\n", "c = (n-1)*e0*er*A/float(d); #capacitance in F\n", " \n", "#result\n", "print'capacitance=%3.4e'%c,'F';" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 6.16,Page No:6.32" ] }, { "cell_type": "code", "execution_count": 12, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "thickness=0.82 mm\n" ] } ], "source": [ "import math\n", "\n", "#variable declaration\n", "e0 = 40000; #dielectric strength in volts/m\n", "d = 33000; #thickness in kV\n", "\n", "#calculations\n", "t = d/float(e0); #required thickness of insulation in mm\n", " \n", "#result\n", "print'thickness=%3.2f'%t,'mm';\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "##Example 6.17,Page No:6.32" ] }, { "cell_type": "code", "execution_count": 13, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "area = 1.30 m**2\n", " breakdown voltage=1.8e+04 V\n" ] } ], "source": [ "import math \n", "\n", "#variable declaration\n", "C = 0.03*10**-6; #capacitance in F\n", "d = 0.001; #thickness in m\n", "er = 2.6; #dielectric constant\n", "e0 = 8.85*10**-12; #dielectric strength \n", "E0 = 1.8*10**7 \n", " \n", "#formula\n", "#C=e0*er*A/d\n", "#e0=v/d\n", "#calculation\n", "A = (C*d)/float(e0*er); #area of dielectric needed in m**2\n", "Vb = E0*d; #breakdown voltage in m\n", "\n", "#result\n", "print'area = %3.2f'%A,'m**2';\n", "print' breakdown voltage=%3.1e'%Vb,'V';" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 6.18,Page No:6.33" ] }, { "cell_type": "code", "execution_count": 14, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "dielectric loss=5684.1 watts\n" ] } ], "source": [ "import math\n", "\n", "#variable declaration\n", "C = 0.035*10**-6; #capacitance in F\n", "tangent = 5*10**-4; #power factor \n", "f = 25*10**3; #frequency in Hz\n", "I = 250; #current in A\n", " \n", " \n", "#calculation\n", "V = I/float(2*math.pi*f*C) #voltage across capacitor in volts\n", "P = V*I*tangent; #dielectric loss in watts\n", "\n", "#result\n", "print'dielectric loss=%3.1f'%P,'watts';\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "# Example 6.19,Page No:6.33" ] }, { "cell_type": "code", "execution_count": 15, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "area=1.129433e-02 m**2\n" ] } ], "source": [ "import math\n", "\n", "#variable declaration\n", "Q = 20*10**-6; #charge of electron in coulomb\n", "V = 10*10**3; #potential in V\n", "e0 = 8.854*10**-12; #absolute permitivity\n", "d = 5*10**-4; #separation between plates in m\n", "er = 10; #dielectric constant\n", "\n", "#formula\n", "#Q=CV\n", "#C=er*e0*A/d\n", "C = Q/float(V);\n", "A = (C*d)/float(er*e0); #area in m**2\n", " \n", "#result\n", "print'area=%1e'%A,'m**2';" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "# Example 6.20,Page No:6.35" ] }, { "cell_type": "code", "execution_count": 16, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "electrial conductivity=2.53e+07 (Ω-m)**-1\n", "lorentz number = 185.33 W/mK\n" ] } ], "source": [ "import math\n", "\n", "#variable declaration\n", "n = 3.0*10**28; #number of electrons per m**3\n", "t = 3*10**-14; #time in s\n", "m = 9.1*10**-31; #mass of electron in kg\n", "L = 2.44*10**-8; #lorentz number in ohm W/K**2\n", "T = 300; #temperature in kelvin \n", "e = 1.6*10**-19; #charge of electron in coulomb\n", "\n", "\n", "#calculation\n", "sigma = (n*(e**2)*t)/float(m); #electrical conductivity in (ohm-m)**-1\n", "K = sigma*T*L;\n", " \n", "#result\n", "print'electrial conductivity=%3.2e'%sigma,'(Ω-m)**-1';\n", "print'lorentz number = %3.2f'%K,'W/mK';\n" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [] } ], "metadata": { "kernelspec": { "display_name": "Python 2", "language": "python", "name": "python2" }, "language_info": { "codemirror_mode": { "name": "ipython", "version": 2 }, "file_extension": ".py", "mimetype": "text/x-python", "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython2", "version": "2.7.6" } }, "nbformat": 4, "nbformat_minor": 0 }